MRI对比增强液体衰减反转恢复序列对脑转移瘤的诊断价值

目的探讨利用MRI对比增强液体衰减反转恢复（FLIAR）序列对脑转移瘤的诊断价值。方法35例患有原发性恶性肿瘤且临床怀疑有脑转移的病人，在静脉注射双倍量Gd-DTPA（0．2mmol／kg）前、后行T1WI和FLAIR序列扫描。比较增强前、后T1WI和FLAIR显示脑转移病变的数目、大小和位置，并分析两者间偏差的原因。结幂35例中有27例出现异常强化病灶，其中3例因有病灶内出血被排除，其余24例中增强后T1WI显示84个病灶，增强后FLAIR显示73个病灶。3例增强后FLAIR较增强后T1WI显示的病灶多，15例两者相同，6例增强后FLAIR显示的病灶少于增强后T1WI。增强后T1WI上因与脑表面小血管混淆而致漏判或误判的6个病灶，在对比增强FLAIR均可明确诊断。结论对比增强FLAIR可以有效显示脑转移病灶，尤其对浅表皮质转移灶的检出和诊断更具优势，对脑转移瘤的显示和判断有较大帮助。

Value of MRI contrast-enhancement FLAIR in the diagnosis of metastatic encephaloma

Objective To evaluate the value of contrast-enhanced fluid attenuated inversion recovery(FLAIR) sequence in the diagnosis of metastastatic encephaloma.Methods Thirty-five patients with primary malignancy and suspected cranial metastases underwent FLAIR and T1W imaging with and without intravenous gadopentetate dimeglumine.The numbers,size and position of metastases displayed on T1WI and FLAIK were compared before enhanecment and after enhancement to analyze the difference between the two sequences.Results Intracranial metastases were demonstrated in twenty-seven patients,of which three patients were excluded for hemorrhage,and twenty-four patient underwent postcontrast T1W images which showed eighty-four lesions and underwent postcontrast FLAIR which showed seventy-three lesions.Compared with T1W images,postcontrast FLAIR images showed more metastases in three patients,and the equal number in fifteen,and fewer lesions in six.Six lesions misdiagnosed in postcontrast T1W images for confusing with superficial small vessels were confirmed in postcontrast FLAIR.Conclusion Contrast-enhanced FLAIR can effectually detect intracranial metastases,and is especially useful for detecting superficial lesions,displaying and judging metastatic encephaloma.